Hingeless ventilator

ABSTRACT

A hingeless ventilator for an opening in a wall having a frame fixable to the wall about the opening, a foraminous plate unitary with the frame for screening the opening, and a closure member on a side of the wall and swingable against the frame at one or each side of the opening for opening and closing the opening. A spring rod on the opposite side of the wall and connected to the closure member by laterally spaced arms, rides on guides fixed to the frame for selectively positioning the closure member, while normally spaced means on the closure member and frame and interfitting during swinging of the closure member substantially fix the latter&#39;&#39;s swinging axis or axes. The arms connecting the spring rod to the closure member are flat and extend through and ride in slots in the screen plate and are so shaped as substantially to fill the slots over their range of relative movement. A locating rib outstanding from the foraminous plate adjacent sides thereof and engaging the inner face of the closure member, either directly or through a sealing gasket thereon, positions the closure member during the initial portion of its swing for later engagement of the interfitting means.

NH Oct. 8, 1974 United States Patent [191 Kelly et al.

[ HINGELESS VENTILATOR a frame fixable to the wall about the opening, aforam- [75] Inventors; Timothy Keny, Salem; David T. inous plate unitarywith the frame for screening thlei e wa opening, and a closure member ona side of th Callahan, Lynchburg, both of Va.

and swingable against the frame at one or each side of the opening foropening and closing the opening. A spring rod on the opposite side ofthe wall and connected to the closure member by laterally spaced arms,rides on guides fixed to the frame for selectively positioning theclosure member, while normally h 7 www m,6fl mma w n GSM4 0. e

o e m N. S e D. S p A FA M MP 7 2 2 .l. l.

spaced means on the closure member and frame and 52 C interfittingduring swinging of the closure member 1 S I 98/2 98/2 18 substantiallyfix the latter s swinging axis or axes. The g rod to the closure memberarms connecting the sprin are flat and extend through and ride in slotsin the screen plate and are so sha [51] Int. B60h l/26 [58] Field ofSearch......................... 98/2, 2.16, 2.18

ped as substantially to fill [56] References Cited the slots over theirrange of relative movement. A locating rib outstanding from theforaminous cent sides thereof and en 8 g gf .fih n n 0 d .n n a m m o sd m t w a a w am a U 6 n n m m e n T. I em 6 a r ul t m gyl. 0 .m cf gclosure member, either directl gasket thereon, positions the the initialportion of its swin the interfitting means.

Primary Examiner-William E. Wayner Assistant Examiner-Peter D. FergusonAttorney, Agent, or Firm-Wilmer Mechlin ABSTRACT A hingeless ventilatorfor an opening in a wall having 11 Claims, 11 Drawing Figures n l s e50000 00000 W OOOOO... 00000 W 00 0 00000 m o 0 00000 0000 w m ww% 000CO 5 w0000 o0000 t t 00000 00000 n w 0000 00000 4 wwm wwwww L t m 00 m 4L m 00000- 00000 m 2 W. 00000 00000 m 00009-00000 m w v/ oooqow ooo W nIt! M u u 3 60000 0000 w 00000- 0000 V 9 8 3 00000, 00000 f OOOOOF OOOOO2 v a 00000.. 0000 \T 000000 0000 H n H. 00000000000 l W 000000000001 m.00000000000 m 000000 0000 n b W 00000 0 0000 J o n m 00000000000 t n o m00000o00000 1 M 00000 0000 t u n m 10000900009 n w .1 z If: a El n 11 tIIINGELESS VENTILATOR BACKGROUND OF THE INVENTION Heretofore, numeroustypes of ventilators have been proposed for ventilating a cab or otherdriver compartment of a self-propelled land vehicle. Particularly intruck and tractor cab installations the need is for a ventilator adaptedalternately to draw air into and exhaust air from the cab. A type ofventilator specifically designed to fill this need is a two-wayhingeless ventilator such as disclosed in Kelly, et al U.S. Pat. Nos.3,102,464 and 3,358,576. As in these patents, the ventilators of thistype have a frame mountable on and bounding an opening in a wall of acab or other enclosure and a closure member outside the wall andswingable against the frame on either side of the opening. The closuremember is held against the frame and in any selected position, suitablyby a spring rod connected for swinging in unison to the closure memberand riding at opposite ends on fixed guides on the opposite side of thewall and instanding from the frame. In the prior pats on two-wayhingeless ventilators a flange out-turned from the frame bounds theopening and the closure member in closed position covers the frameflange and has an in-turned marginal flange surrounding and overlappingthe frame flange and engagable with the latter at either side of theopening for substantially fixing the axis about which the closure memberswings in either direction.

In U.S. Pat. No. 3,358,576 it was recognized that the opening in theframe should be screened to prevent entry of bugs or other foreignmatter in the forwardly open position of the closure member and that thescreening would automatically be cleaned of such matter by the airflowreversal when the closure member was opened toward the rear. Thesolution disclosed in the patent is the use of screen sections mountedin brackets on the frame with slots in or at ends of the screen toaccommodate arms extending therethrough for connecting the spring rod tothe closure member for swinging in unison therewith and resilient flapsat both sides of each slot for sealing the slots over the range ofswinging of the closure member. Also directed to a two-way hingelessventilator, the present invention is particularly concerned with animproved solution to the problem of screening an opening in the frame.

SUMMARY OF THE INVENTION The primary object of the present invention isto provide an improved hingeless ventilator, having a frame and closuremember, wherein a foraminous plate unitary with the frame not onlyscreens an air opening in but also strengthens the frame.

Another object of the invention is to provide a two way hingelessventilator having a frame and closure member, wherein an air opening inthe frame is screened by a foraminous plate unitary with the frame and aspring rod for holding the closure member in selected position isconnected to the closure member by flat arms spaced longitudinally ofthe closure member and having bases fixed to and extending substantiallyacross the closure member, and the connecting arms extend through slotsin the foraminous plate and are so shaped as substantially to closetheir slots over the range of movement of the closure member, wherebythe arms can be thinner and the slots narrower than heretofore possibleand the noise of the air passing through the opening is veryconsiderably reduced.

An additional object of the invention is to provide a two-way hingelessventilator having a frame and closure member, in which an air opening isscreened by a foraminous plate unitary with and offset outwardly from amounting flange of the frame and connected thereto by a web bounding theopening, the swinging axis of the closure member on either side of theopening is substantially fixed after initial opening by engagement ofinterfittable elements on the closure member and frame, and means on theframe and either directly or indirectly engaging an inner face of theclosure member restrain the closure member in and adjacent closedposition against lateral displacement relative to the frame.

A further object of the invention is to provide a twoway hingelessventilator in which a spring rod for holding a closure member inselected position is connected adjacent opposite ends to the closuremember by a bail fixed to the closure member and the rod is deflectedfor tensioning toward the closure member by means on the bail.

Other objects and advantages of the invention will appear hereinafter inthe detailed description, be particularly pointed out in the appendedclaims and be illustrated in the accompanying drawings, in which:

FIGURE DESCRIPTION FIG. 1 is an inner plan view of an embodiment of theimproved hingeless ventilator of the present invention showing theventilator mounted in an apertured wall.

FIG. 2 is a longitudinal sectional view of the ventilator of FIG. Iremoved from the wall and taken along lines 2-2 of that figure.

FIG. 3 is a transverse sectional view taken along lines 3-3 of FIG. 1.

FIG. 4 is a transverse sectional view taken along lines 4-4 of FIG. 1.

FIG. 5 is an end elevational view taken from lines 5-5 of FIG. 1 withthe closure member in open position.

FIG. 6 is a fragmentary transverse sectional view on the section of FIG.4 but an enlarged scale showing the action of the positioning meansduring the initial opening movement of the closure member.

FIG. 7 is an inner plan view of another embodiment of the improvedventilator.

FIG. 8 is a longitudinal sectional view taken along lines 88 of FIG. 7.

FIG. 9 is an end elevational view taken from lines 9-9 of FIG. 1 withthe closure member shown in partly open position.

FIG. 10 is a fragmentary transverse sectional view on a larger scaletaken along lines 10-10 of FIG. 7, and

FIG. 11 is a fragmentary transverse sectional view on the scale of FIG.10 taken along lines 11-11 of FIG. 7.

DETAILED DESCRIPTION Referring now in detail to the drawings in whichlike reference characters designate like parts, the improved hingelessventilator of the present invention, while applicable for controllingthe flow of air into an enclosure, is designed primarily for applicationa two-way ventilator to a cab or other enclosure of a vehicle fordirecting air into or from the enclosure while the vehicle is in motion,and will be so described as exemplary of the invention.

In the preferred two-way form illustrated in the accompanying drawings,the ventilator of the present invention is similar to those of Kelly, etal. U.S. Pats. Nos. 3,102,464 and 3,558,576 in having a frame 1 fixableor securable to a suitably apertured exterior wall 2 of a vehicle cab orother enclosure (not otherwise shown) and having a generally rectangularcentral opening 3 opening through the wall, a closure member, cover ordoor 4 seatable against an outer side of and swingable on the frame foropening and closing the opening, spaced guides 5 fixed to and instandingfrom an inner side of the frame at opposite ends of the opening, and aguide rod 6 connected to the closure member and having ends riding onthe guides for holding the closure member assembled and in any selectedposition relative to the frame.

As in the hingeless ventilators of the above and other Kelly and Kelly,et al. patents, the frame 1 has a mounting or base flange 7 attached,fixed or secured, when installed, to the inside of the vehicle wall 2about the aperture 8 therein and terminated or bounded inwardly by anout-turned lip 9 outstanding from and substantially normal to andunitary or integral with the mounting flange and laterally surroundingor bounding the frame opening 3. The closure member 4 is of the samegenerally rectangular shape as the opening 3 and has a suitably flatbody or main part 10 of an area to fit over and close the frame openingin the closure members closed position. In the same closed position anintumed marginal flange or skirt 11 extending around the periphery ofand instanding from and substantially normal to the body 10, surroundsand overlaps the lip 9 and is then or normally spaced from both the lipand the mounting flange 7 so as not to interfere with closing of theopening 3. When closed, the closure member preferably seals the opening3 weatheror airtight, suitably by a sealing gasket 12 in the form of agenerally rectangular band or sheet of rubber or like resilient materialcarried by and fixed as by bonding to and covering at least theperipheral portion of the members inner face 13. Whether a band or asheet, the sealing gasket 12 extends from the skirt ll inwardly beyondand overlaps the fr'ames lip 9 in the closed position of the closuremember 4.

In use for ventilating a cab or other compartment of a vehicle, theillustrated two-way ventilator is designed to be so installed orpositioned that the closure member 4 can be opened longitudinally of thevehicle and alternately toward the latters front and rear. Thus,depending on the direction in which the closure member is opened, theventilator, while the vehicle is moving, will direct air either into orfrom the compartment, the former by the pressure and the latter by thesuction exerted by movement of the vehicle relative to ambient air. Toprevent entry of bugs or other foreign solid matter or debris in theventilators forwardly or front open condition, the opening 3 in theframe 1 is screened and, as opposed to the separate wire screening ofKelly, et al. U.S. Pat. No. 3,358,576, by a screen 14 unitary orintegral with the mounting flange 7 and forming an integral part of theframe 1. The preferred screen 14 is a flat foraminous or perforatedplate offset outwardly from the mounting flange 7 and peripherallyconnected or joined thereto through the outstanding lip or connectingweb 9. Disposed parallel to the mounting flange 7 or at least the flatportion thereof adjacent the connecting lip or web 9, the screen plate14 suitably has holes or perforations 15 arranged in longitudinally andtransversely extending rows, with each hole of a size or diameter topass air while substantially obstructing or inhibiting passage of bugsor other foreign solid matter.

The one-piece or unitary frame or frame assembly 1, including themounting flange 7, connecting lip 9 and screen plate 14, while otherwiseformable, is particularly adapted to be formed by stamping from a sheetof suitable metal in a single operation in which the frame is given thedesired shape and the holes 15 are punched in the desired arrangementthrough the screen plate. Offset outwardly from and peripherallyconnected by the lip or web 9 to the mounting flange 7, the screen plate14 additionally acts as a stiffening or reinforcing member, the presenceof which rigidifies the frame and enables it, relative to previousventilator frames, to be made of thinner sheet steel or even aluminum,without sacrificing strength.

As in the prior Kelly and Kelly, et al., patents, the axis about whichthe closure member 4 swings at either side of the opening 3, issubstantially fixed by the interfit or interengagement of parts of theclosure member 4 and frame 1, suitably the side portions of the lip 9 ofthe frame and skirt 11 of the closure member at corresponding sides ofthe opening. Over most of the range of swinging of the closure memberrelative to the frame at one side of the opening 3, the side portion ofthe skirt at the opposite side of the opening, under the tensile orpulling force of the spring rod 6, engages and acts against theadjoining side portion of the lip and seats or is received in oradjacent the bend at that side between the lip and the mounting flange 7for substantially fixing the axis about which the closure member swings.By contrast, when the closure member is in closed or normal position,the skirt 11 should be spaced laterally from the lip 9 to preventinterference with closing of the closure member. With such normalspacing of the skirt and lip there thus is a relatively small transitionarc in the range of movement of the closure member adjacent closedposition, as it initially moves from and. completes its return to thatposition, when the closure member is not restrained by the skirt and lipagainst lateral movement relative to the closure member.

Unless otherwise restrained, the closure member 4 can shift or movelaterally relative to the frame 1 in the plane of the mounting flange 7not only during the transition period but also in closed position, withconsequent possible jamming and impairment of the ventilators openingaction. Were the outer end of the lip 9 exposed, as in Kelly, et al.U.S. Pat. No. 3,358,576, the restraint against lateral shifting could beimposed by the pressing of the outer edge of the lip into the resilientgasket 12 on the inner face 13 of the closure member. However, in thepresent ventilator, such coaction of the lip and gasket is precluded bythe merging of the lip with the screen plate 14 at their juncture.Instead, the present ventilator depends for restraining relativeshifting of the closure member 4 and frame 1 upon 10- cating orpositioning rib or boss means outstanding or projecting or extendingoutwardly from the screen plate and indenting or pressing into andacting on the sealing gasket 12 and therethrough the inner face 13 ofthe closure member both in the latters normal or closed position andduring the transition period.

Consistent with the preferred forming of the frame 1 by stamping, thepreferred locating rib means are a continuous rib, boss or embossment l6pressed, bumped or stamped into the frame and projecting outwardly oroutstanding from and extending around the periphery of the screen plate14 outside the perforations 15 and inside the lip 9. Suitably interposedbetween and merging on opposite sides with and integrally joining orconnecting the screen plate 14 and lip 9, the preferred continuouslocating rib 16 not only restrains the closure member 4 against lateralshifting from centered position relative to the frame, but by normallyindenting or pressing into the sealing gasket 12 about the opening 3,also increases the efficiency of the sealing gasket as a weather seal inthe closed position of the closure member. Over a plurality of suitablyspaced individual locating ribs, the preferred continuous rib 16 isadvantageous in eliminating any unrelieved stressing of the frame andcan perform with the sealing gasket 12 its intended functions ofrestraining relative lateral movement and sealing against weather, evenwhen, as illustrated, U-shaped in cross-section with an arcuately convexor rounded nose, apex or leading or gasket-presented edge 17 for minimalabrasion of the sealing. gasket.

Riding at opposite ends, either directly or through inwardly cappedNylatron or like anti-friction rollers 18, on the spaced guides or guidemembers 5 fixed to and instanding from the mounting flange 7 of theframe 1 at opposite ends of the opening 3, the spring guide or controlrod 6 is connected adjacent opposite ends to the closure member 4 byarms 19 extending through the opening 3 and rectangular slots 20 in theend portions of the screen plate 14 beyond the perforations 15 therein.Disposed or extending transversely of the closure member 4, thepreferred arms 19 are flat and generally pear-shaped or pyriform inoutline or front or face elevation, with inturned feet or base flanges21 fixed as by welding to the members inner face 13 and bodies 22 normalto and instanding from that face and their feet. Peripherally ormarginally semi-ovoidal and flaring outwardly toward or taperinginwardly from the closure member, the bodies 22 at their relatively wideouter or foot-connected extremities and the feet 21 are of substantiallythe width of the perforated area of the screen plate 14 and extendsubstantially to the peripheral portion of the inner face 13 covered bythe corresponding portion of the sealing gasket 12, while beingcontained laterally or transversely within the locating rib 16 in theclosed position of the closure member. Each body 22 has counterpart,arcuately, preferably circularly convex opposite marginal edges,peripheries or sides 23, and each of which is substantially struck aboutor concentric with the swinging axis of the closure member 4 at theopposite side of the opening 3. Outwardly or away from the closuremember 4 and beyond the bodies 22, the arms 19 terminate in suitablyparallel-sided, round-ended heads or extensions 24 coplanar with theirbodies and having apertures or slots 25 elongated longitudinally of thearms and normal to the closure member for receiving and accommodatingany relative longitudinal play of the end portions of the guide rod 6.

Enabled by their wide-based pear-shape to be fixed to the inner face 13of the closure member 4 adjacent opposite sides thereof, the connectingarms 19 not only stiffen the closure member over the areas covered bytheir feet 21 but are themselves of ample strength even when thinnerthan the connecting arms of previous hingeless ventilators.Additionally, with their marginal edges 23 each struck about theopposite swinging axis of the closure member, the width of the bodies 22in the slots 20 or the plane of the screen plate 14 will besubstantially uniform. over the range of angling or swinging of theclosure member relative to the frame. With the areas of the slots 20occupied by the bodies 22 correspondingly uniform over the range ofrelative movement of the closure member, it thus is both possible andpreferred to hold the dimensions of the slots to tolerances relative tothe width and thickness of the arms such that the open or unoccupiedarea of the slots at any point is of about the same width as each of'the perforation 15. Consequently, when of the preferred shape andrelative dimensions, the arms 19 and slots 20 are as effective as theperforated area of the screen plate 14 in screening the opening 3 and,by markedly reducing in the ventilators open position the slot areasleft open by previous parallel-sided connecting arms, correspondinglysmoothing the flow and reducing the noise of the air passing through theslots and eliminating any need for sealing flaps.

Alike in the foregoing respects, the ventilators of the embodiments ofFIG. 1 and 7 are also alike in their spaced guides 5. Thus, in eachembodiment the guides 5 fixed to the mounting flange 7 of the frame 1 atopposite ends of the opening 3 are bent or bowed intermediate theirends, conveniently by bending or stamping them from strip metal, andeach presents on opposite sides for engagement by the adjoining end ofthe guide rod 6 arcuately and preferably cylindrically convex guidesurfaces or guideways 26. As are the cylindrically convex sides 23 ofthe connecting arms 19, the preferred guide surfaces 26 on the sides ofthe guides or guide members 5 are each substantially concentric orcoaxial with and struck about the swinging axis of the closure member 4at the opposite side of the opening 3 so as to enable the tensile forceapplied to the closure member 4 by the spring rod 6 to be substantiallyuniform over the range of open positions of the ventilator. At theirinner or adjoining extremities the guide surfaces 26 merge with and areconnected or joined by an arcuately convex apex 27 of relatively shortradius on which the adjoining end of the guide rod 6 rests or ispositioned in the closure member's closed position.

Aside from somewhat differently configured mounting flanges 7 to suitparticular installations, the differ ence between the embodiments ofFIGS. 1 and 7 resides in the manner in which the tensile or pullingforce of the spring rod 6 is applied to the closure member 4. In bothembodiments the tensile force is generated by deflecting, bending orbowing the longitudinal or axial mid-portion of the guide rod 6outwardly toward the closure member 4. In the embodiment of FIG. 1 thedeflection is produced by a central tensioning or deflecting arm 28centered on and fixed to the inner face 13 of the closure member 4.Otherwise suitably identical with the connecting arms 19 and identicallyrelated to its slot 29 in the screen plate 14, the tensioning arm 27receives the guide rod 6 in a head slot 30 of an area to accommodate andpass the guide rod during assembly and disassembly but so spaced oroffset outwardly toward the closure member 4 relative to the head slots25 of the connecting arms 19 as to centrally bend, bow or deflect theguide rod toward the closure member by an amount predetermined to applythe desired tensile or pulling force to the closure member. For correctpositioning of the guide rod 4 longitudinally relative to the tensioningarm 28, the former has at the center an annular notch or groove 31 forreceiving or fitting the outer edge of the head slot 30 in thetensioning arm.

In the embodiment of FIG. 7, the connecting arms 19 are the onlyconnections or links between the guide rod 6 and the closure member 4but the head 24 of the arms are relatively longer than those of thefirst embodiment and suitably notched at their inner extremities or endsto receive the ends of the web portion 32 of a bail or handle 33. Without-turned legs 34 at opposite ends straddling and connected or fixed,as by riveting, to the heads 24 of the arms 19 inwardly of or beyond thehead slots 25 therein, the bail 33 over its web portion 32, suitably isstraight and substantially parallel to the guide rod 6 andlongitudinally reinforced by a central rib 35 pressed or stampedtherein. With the ribreinforced bail 33 providing a rigid backing orplatform, the outward central deflection of the spring rod 6 in thissecond embodiment is produced by a conveniently V-shaped, arch orpressure bar 36 fixed to and extending longitudinally of the web portion32. Outstanding or projecting outwardly from the outward or underside ofthe web portion 32, the pressure or deflecting bar 35 has as its outwardextremity an apex or nose 37 engaging and acting on the spring rod 6,conveniently through the central annular positioning or locating grooveor notch 31 in the rod, for deflecting r bending the rod outwardlytoward the closure member 4 to the extent predetermined to provide thedesired tensile force on the closure member 4.

As pointed out in Kelly U.S. Pat. No. 3,760,707, unless restraintagainst twisting relative to the guide members is imposed on the springrod 6, an excessive twisting force applied toward one end of the rod, asby a kickof an operator, can force the ends of the rod to engageopposite sides of the guide members, in which case the ventilator willbecome inoperative and can even lose the closure member. In that patentthe restraint against relative twisting is imposed by guiding the endsof the rod in double-bracketed guide members. However, in the presentventilator such guide members are unnecessary since the relatively largearea constantly presented to the screen plate 14 by the wide connectingarms 19 and, if present, the tensioning arm 28 and the close fit of eacharm in its slot or 29, effectively prevent twisting of the rod 6relative to the guide members 5, thus rendering the ventilator proofagainst failure even when subjected in operation to excessive twistingforces.

Depending on the embodiment, the operator will use either the spring rod6 or the bail 33 as a handle for swinging the closure member 4 to aselected position and, with the tensile force substantially uniform inthe closure members open positions and preferably slightly greater inits closed position, the closure member will remain or be held in anyselected position relative to the frame 1 until later swung or movedtherefrom. Held against lateral movement relative to the frame in andadjacent closed position and therebetween by the interactionrespectively of the locating rib l6 and sealing gasket 12 and of theadjoining side portions of the skirt 11 and lip 9, the closure memberwill always be positioned to open and close smoothly and provide aneffective weather seal when closed, while the integral screen plate 14on the frame 1 screens the opening 3 whenever the closure member isopened. Catching bugs and like debris on its outer surface when theclosure member is opened toward the front, the screen plate will beautomatically cleaned of any collected debris by the air outflowing fromthe compartment when the closure member is opened toward the rear.

From the above detailed description it will be apparent that there hasbeen provided an improved hingeless ventilator, which by having a screenas an integral reinforcing part of a frame readily formable in one pieceand connecting arms so configured as effectively to screen slots in thescreen through which they extend, is relatively simple in construction,very rugged and economical to produce. It should be understood that thedescribed and disclosed embodiment is merely exemplary of the inventionand that all modifications are intended to be included that do notdepart from the spirit of the invention and the scope of the appendedclaims.

Having described our invention, we claim:

1. A hingeless ventilator for ventilating a compartment through anopening in a wall thereof, comprising a unitary frame assemblyattachable to said wall about said opening and having screening meansintegral therewith for screening said opening, a closure memberswingable against a side of said frame for opening and closing saidopening, guide means fixed to and instanding from an opposite side ofsaid frame at opposite ends of said opening, means connected to andswingable with said closure member and riding on said guide means forholding said closure member in selected positions relative to saidframe, and interacting means on said frame and closure member forrestraining relative lateral movement therebetween over the range ofmovement of the closure member.

2. A hingeless ventilator according to claim 1, wherein the screeningmeans is a perforated screen plate connected to and offset outwardlyfrom a mounting flange of the frame, the holding means is a spring rodriding at ends on said guide means, and the interacting means includelocating rib means on said frame and outstanding from said screen plateand acting on said closure member, and normally laterally spaced flangemeans on said frame and closure member and interfitting on partialopening of said closure member.

3. A hingeless ventilator according to claim 2, including a sealinggasket on an inner face of said closure member and coacting with saidlocating rib means for sealing about the opening in the closure membersclosed position and locating said closure member relative to the framewhen the flange means are disengaged.

4. A hingeless ventilator according to claim 3, wherein the locating ribmeans are a continuous rib extending around the screen plate, and theflange means are a web outstanding from the frame about the openingbetween and connecting the screen plate and a mounting flange of theframe and a peripheral skirt instanding from the closure member and inthe closed position thereof surrounding said web.

5. A hingeless ventilator according to claim 3, including longitudinallyspaced arms fixed to the inner face of the closure member and instandingtherefrom through slots in the screen plate and connected to oppositeend portions of the spring rod, and the connecting arms havesemi-ovoidal body portions riding in said slots over the range ofmovement of the closure member, said body portions being flat and havingon opposite sides cylindrically convex surfaces each substantiallyconcentric with a swinging axis of the closure member at an oppositeside of the opening, and said slots being so dimensioned relative tosaid body portions as to be screened thereby in open positions of theclosure member.

6. A hingeless ventilator according to claim 5, wherein the screen plateis perforated between the connecting arm slots therein by spacedperforations arranged in rows.

7. A closure member, according to claim 6, including a tensioning armfixed to the closure member and connecting midportions thereof and thespring rod for defleeting the rod outwardly toward the closure member,and the tensioning arm has a body portion identical with the bodyportions of the connecting arms and identically related to a slottherefor in the spring plate.

8. A hingeless ventilator according to claim 6 including a bail fixed toand connecting the connecting arms inwardly of the spring rod, and meansfixed to and outstanding from a web portion of the bail and acting on amid-portion of the rod for tensioning the rod.

9. A hingeless ventilator according to claim 8, wherein the web portionof the bail is longitudinally reinforced by rib means integraltherewith, and the tensioning means is an arch bar having at its innerextremity an apex fitting in an annular locating groove in themid-portion of the rod.

10. A hingeless ventilator according to claim 1, including arms spacedlongitudinally of and fixed to the closure member for connecting theconnected means thereto, said arms instanding from the closure memberthrough slots in the screening means and cooperating through said slotswith the screening means for preventing twisting of the closure memberrelative to the frame assembly.

11. A hingeless ventilator according to claim 10, wherein areas of thearms presented in the slots to the screening means are substantiallyuniform over the range of swinging of the closure member relative to theframe assembly.

1. A hingeless ventilator for ventilating a compartment through an opening in a wall thereof, comprising a unitary frame assembly attachable to said wall about said opening and having screening means integral therewith for screening said opening, a closure member swingable against a side of said frame for opening and closing said opening, guide means fixed to and instanding from an opposite side of said frame at opposite ends of said opening, means connected to and swingable with said closure member and riding on said guide means for holding said closure member in selected positions relative to said frame, and interacting means on said frame and closure member for restraining relative lateral movement therebetween over the range of movement of the closure member.
 2. A hingeless ventilator according to claim 1, wherein the screening means is a perforated screen plate connected to and offset outwardly from a mounting flange oF the frame, the holding means is a spring rod riding at ends on said guide means, and the interacting means include locating rib means on said frame and outstanding from said screen plate and acting on said closure member, and normally laterally spaced flange means on said frame and closure member and interfitting on partial opening of said closure member.
 3. A hingeless ventilator according to claim 2, including a sealing gasket on an inner face of said closure member and coacting with said locating rib means for sealing about the opening in the closure member''s closed position and locating said closure member relative to the frame when the flange means are disengaged.
 4. A hingeless ventilator according to claim 3, wherein the locating rib means are a continuous rib extending around the screen plate, and the flange means are a web outstanding from the frame about the opening between and connecting the screen plate and a mounting flange of the frame and a peripheral skirt instanding from the closure member and in the closed position thereof surrounding said web.
 5. A hingeless ventilator according to claim 3, including longitudinally spaced arms fixed to the inner face of the closure member and instanding therefrom through slots in the screen plate and connected to opposite end portions of the spring rod, and the connecting arms have semi-ovoidal body portions riding in said slots over the range of movement of the closure member, said body portions being flat and having on opposite sides cylindrically convex surfaces each substantially concentric with a swinging axis of the closure member at an opposite side of the opening, and said slots being so dimensioned relative to said body portions as to be screened thereby in open positions of the closure member.
 6. A hingeless ventilator according to claim 5, wherein the screen plate is perforated between the connecting arm slots therein by spaced perforations arranged in rows.
 7. A closure member, according to claim 6, including a tensioning arm fixed to the closure member and connecting midportions thereof and the spring rod for deflecting the rod outwardly toward the closure member, and the tensioning arm has a body portion identical with the body portions of the connecting arms and identically related to a slot therefor in the spring plate.
 8. A hingeless ventilator according to claim 6 including a bail fixed to and connecting the connecting arms inwardly of the spring rod, and means fixed to and outstanding from a web portion of the bail and acting on a mid-portion of the rod for tensioning the rod.
 9. A hingeless ventilator according to claim 8, wherein the web portion of the bail is longitudinally reinforced by rib means integral therewith, and the tensioning means is an arch bar having at its inner extremity an apex fitting in an annular locating groove in the mid-portion of the rod.
 10. A hingeless ventilator according to claim 1, including arms spaced longitudinally of and fixed to the closure member for connecting the connected means thereto, said arms instanding from the closure member through slots in the screening means and cooperating through said slots with the screening means for preventing twisting of the closure member relative to the frame assembly.
 11. A hingeless ventilator according to claim 10, wherein areas of the arms presented in the slots to the screening means are substantially uniform over the range of swinging of the closure member relative to the frame assembly. 